Generally, in cellular mobile communications, when a mobile terminal moves from a cell to another cell, the mobile terminal performs handover for switching between radio base station apparatuses as a communicating party. With respect to the handover function in the data link layer and lower layers, required QoS (Quality of Service) in the data link layer and lower layers is guaranteed by macro diversity between cells. In handover between cells, when high-speed packet scheduling and ARQ (Automatic Repeat Request) is considered, it is desired that the cell switching period is 100 ms.
Meanwhile, in UMTS (Universal Mobile Telecommunications System) networks, for the purpose of improving spectral efficiency and further improving data rates, by adopting HSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Packet Access), it is performed exploiting maximum features of the system based on W-CDMA (Wideband Code Division Multiple Access). For the UMTS network, for the purpose of further increasing high-speed data rates, providing low delay and the like, Long Term Evolution (LTE) has been considered (Non-patent Document 1). Further, in the UMTS network, for the purpose of further increasing the wide-band and high speed, next-generation systems to LTE have been considered (for example, LTE Advancement (LTE-A), IMT Advance (IMT-A)).